The present invention relates to a device as well as a procedure for forming a point on the ends of wires.
Particularly when retracting wires in wire drawing machines, it is necessary to form a point on the ends of the wires to be retracted so that same can be threaded into the next respective die.
A device for forming points on wire tips is already known in which the ends of the wires to be pointed are cold-formed between two rollers. The surfaces of the rollers have slots with increasing groove depth so as to produce a rounded cross-section of a wire end progressing essentially pointed.
Forming wire tips with said known device is, however, costly and time-intensive. Moreover, pointed wire tips manufactured with such a device exhibit burrs which are often unwanted.
It is thus the task of the present invention to produce a device for forming points on the ends of wires which is economical to manufacture, enables fast and burr-free wire end tips, and which can be flexibly adapted to different wire diameters.
The task is solved by a device for the forming of points on the ends of wires in accordance with the present invention.
In accordance with the present invention, a device is in particular provided for the forming of points on the ends of wires which comprises a first and a second means for the receiving of a wire, as well as a heating device and a means for stretching the wire according to predetermined conditions.
The heating device is preferably configured as an electric resistance heater or electrical heating means. Especially preferred is the heating means comprising at least one first contact point as well as at least one second contact point, respectively at least one first pole and at least one second pole. Said poles are preferably connected to a transformer. By means of these poles, hereinafter referred to as contact points, each heating means comes into contact with one respective section of the wire to be pointed. Hereby, a voltage drop occurs between said contact points, meaning especially within said wire, so that a current flows through the conductive wire, thereby inducing a heating of the wire in the section between the contact points.
According to the present invention, the heating means may also be of a different configuration.
The wire is braced against the first as well as the second receiving means. Said first and/or second receiving means respectively preferably comprises a clamping means in which the wire is clamped. Said clamping means can be configured as clamping pliers or be disposed with a rotatable, wedge-shaped disc as well as an adjustable lever having a conical point, whereby said disc is particularly configured as a tractive disc. Said tractive disc can preferably be operated either manually, or by a drive means comprising a motor, or in some other way. The clamping means may also be of a different configuration.
The heating device is such designed and arranged that the wire becomes heated between the first and the second receiving means.
Preferably, said first electrical contact point of said electrical heating means, respectively resistance heater, is disposed on said first receiving means and said second electrical contact point of said electrical heating means, respectively resistance heater, is disposed on said second receiving means.
It is also preferred that said electrical contact points are not disposed on said first receiving means or said second receiving means, which preferably are provided with clamping means for clamping the wire, or that only one of said receiving means has an electrical contact point.
According to the present invention, a further means is provided which stretches the wire in the heated section according to predefined conditions, in particular doing so in a longitudinal direction to the wire axis.
Especially preferred is using the inventive device as follows: By means of the heating device, configured in particular as a resistance heater, a section of wire in an area between the first and the second receiving means is heated. To this purpose, it is especially provided that the poles, respectively electrical contact points of said resistance heater are arranged on said first receiving means as well as on said second receiving means. The wire is preferably heated long enough to reach incandescence. During this heating or after having been heated, a means is utilized to stretch the wire in the heated section.
The first and the second receiving means, respectively the first and the second contact point, are preferably arranged to be relatively movable with respect to one another.
Especially preferred is that the first receiving means, respectively the first electrical contact point, is fixedly arranged and the second receiving means, respectively the second electrical contact point, is arranged to be rotatable or axially displaceable. The second contact point is particularly preferably arranged on the second receiving means such that upon axial mobility, said receiving means likewise displaces axially and upon rotation, the second receiving means follows a circular path.
This stretching of the heated, respectively incandescent section, can in particular induce that the wire initially tapers and ultimately breaks off. This tapering, respectively breaking off, results in a pointed wire tip. The configuration of the pointed wire as well as the length of the pointed segment can be influenced in different ways. For example, by varying the distance between the electrical contact points or the voltage of the resistance heater, respectively the temperature which the heating means generates in the wire, or the length of heating time, in particular in conjunction with the magnitude and duration of the force generated in the wire, or in other ways.
Preferably, the first contact point is arranged on a clamping member of said clamping means of said first receiving means such that the electrical contact point is pressed against the wire when the clamping member stresses the wire.
It is preferred, in corresponding manner, that a second contact point is arranged on a second clamping member of said clamping means of said second receiving means.
The clamping member is preferably disposed with a threading in which it is led.
It is preferred that said first receiving means and/or said second receiving means is configured as a clamping means and in fact in such a way that wires of different diameters or wires having differing cross-sectional geometries may be clamped.
The device according to the present invention can be used for forming points on various types of wire materials such as, for example, superconductor, CrNi, German silver, or wires made from other types of material.
The inventive device can furthermore be used with wires having different cross-sectional profiles such as triangular, rectangular, polygonal, or rounded or other cross-sectional profile configurations.
The inventive device may be integrated in a wire drawing machine or may be a separate device which, for example, can be moved on rollers or by other similar means.
The inventive device can in particular be used to form points on wires which are drawn in rough drawing processor, whereby the wire diameter is preferably between a range of 2 mm-8 mm. The device according to the present invention is however also preferred for wires of other diameters.
The second receiving means, which is preferably disposed with a second electrical contact point, is movable relative the first receiving means via a drive means such as a motor or the like, or manually.
The present invention especially provides for heating a wire at a predetermined section and particularly in such a manner that it glows reddish and is subsequently stretched in at least the area of this section in the longitudinal direction of the wire axis such that the wire initially tapers and ultimately breaks off, forming a pointed tip at the end of the wire.
In a particularly preferred procedure of the present invention, the wire is heated by means of an electrical resistance heater.
In a preferred procedure of the present invention, the wire is clamped between two points separated by a clearance and is heated in the (or in one) intermediate region between said two points. The wire is then subsequently stretched, wherein one clamping point is moved relative the other clamping point. This induces the wire to taper and break off, forming a pointed wire tip.
The present invention is not to be limited by either its preferred embodiments nor by the examples as given.
In the following, the invention will be described in greater detail using exemplary, nonrestricting embodiments of the present invention, which show: